Suspension stabilizers

ABSTRACT

This invention relates to the use of rubber-like homopolymers and copolymers of conjugated diolefines or of cycloalkenamers as dispersion agents for the suspension condensation of epihalohydrins and polyalkylene polyamines.

Elite States aient 91 Naumann et a1.

3,725,313 Apr. 3, 1973 SUSPENSION STABILIZERS Inventors: GiinterNaumann; Nikolaus Sch'cin, both of Leverkusen; Ilildegard Schniiring,Wuppertal-Elberfeld; Gottfried Pampus, Leverkusen, all of GermanyAssignee: Bayer Aktiengesellscllaft, Leverkusen, Germany Filed: Apr. 9,1971 Appl. No.: 132,913

Foreign Application Priority Data Apr. 18, 1970 Germany ..P 20 18 733.1

US. Cl. ..260/2.1 R, 260/2 BP Int. Cl. ..C08g 23/12 Field of Search..260/2.l R

[56] References Cited UNITED STATES PATENTS 3,005,786 10/1961 Greer..260/2.1

This invention relates to the use of rubber-like homopolymers andcopolymers of conjugated diolefines or of cycloalkenamers as dispersionagents for the suspension condensation of epihalohydrins andpolyalkylene polyamines.

4 Claims, No Drawings SUSPENSION STABILIZERS The preparation ofcondensation products of polyalkylene polyamines with epihalohydrins inthe form of beads and the use of such condensates as anion exchangers isalready known.

According to US. Pat. No. 3,005,786, a precondensate of epihalohydrinand polyalkylene polyamine may be prepared in the presence of water andsuspended in an organic liquid which contains a dispersing agent, andpolycondensation may then be completed in the suspension. Polycondensatebeads which may be used as ion exchangers are obtained.

It has also been tried to carry out this method of preparation withoutthe step of precondensation. In this case, one starts with a suspensionof water in an organic liquid and the two monomers are introduced intothe suspension one after the other and condensed to form beads. For thismethod it is also advantageous to use a dispersing agent.

The dispersion agents hitherto used for this polycondensation are notsatisfactory. They give rise to beads of irregular shape covering a verywide range of sizes. Moreover the results are difficult to reproduce.Bead condensates which are used as ion exchangers should have particlesizes ranging from about 0.4 mm to about 0.8 mm because larger beadshave less exchange capacity whereas smaller beads congest'the usual ionexchanger filters.

This invention relates to the use of rubber-like homopolymers andcopolymers of conjugated diolefines or of cycloalkenamers as dispersionagents for the suspension condensation of epihalohydrins andpolyalkylene polyamines.

Suspension condensation in this context denotes the processes mentionedabove for the production of polycondensates from epihalohydrins andpolyalkylene amines. The usual method of carrying out this process willnow be described briefly.

1 Mol of polyalkylenepolyamine is first dissolved in 10 to 50 mols ofwater and the solution is cooled to about 10 to 30 C. l to 4 mols ofepihalohydrin are then slowly added to this solution with constantcooling so that the reaction temperature does not rise substantiallyabove C. Condensation takes place to yield a syrupy mass. This mass isthen suspended with stirring in an organic liquid which is not misciblewith the syrup; this is carried out in the presence of about 0.01 to 5percent by weight of a dispersing agent, based on the amount of organicliquid. The suspended droplets of syrup are hardened by heating totemperatures of up to 150 C. and then isolated by the usual methods ofseparating liquids and solids, e. g. by filtration.

Polyalkylene polyamines which are suitable for the process are, forexample, those which contain 1 to 10 NH groups attached to two to fourcarbon atoms by alkylene radicals. Examples of such polyalkylenepolyamines are diethylene triamine, triethylene tetramine,tetraethylenepentamine and pentaethylenehexamine.

Suitable organic liquids are hydrocarbons or halogenated hydrocarbons,especially aromatic hydrocarbons, in which the precondensate isinsoluble. Orthodichlorobenzene and mixtures of orthodichlorobenzenewith chlorobenzene and/or with isododecane have been found to beespecially suitable.

Alternatively, precondensation may be omitted, in which case water isfirst suspended in the organic liquid and the polyalkylenepolyamine isthen added, followed by the epihalohydrin. The conditions are otherwisethe same. Care should be taken, however, to ensure that the density ofthe organic liquid does not differ substantially from the density ofthe. monomers which are to be reacted.

According to the invention, the dispersing agents used for this processare rubber-like homopolymers and copolymers of a conjugated diolefinesand/or cycloalkenamers in quantities of 0.01 to 5 percent by weightbased on the weight of the organic liquid. Compounds especially suitablefor this purpose are homopolymers of conjugated diolefines such asbutal,3-diene, isoprene or penta-1,3-diene, polymers of mixtures ofthese diolefines and copolymers of these diolefines with a-olefines suchas styrene, acrylic esters and isobutylene. The method of preparing suchcopolymers is known. The copolymers are generally prepared in organicsolutions alkali metal alkylene or organometallic mixed catalysts of theZieglertype. So-called alfin catalysts or cationic catalysts are alsoused; polymerization may also be carried out with radical catalysts inemulsion or dispersion. Especially suitable polymers are cis-l,4-polybutadiene, cis-l ,4- polyisoprene, styrene butadiene rubber inwhich the monomers are distributed statistically or in blocks, andisobutylene'isoprene copolymers.

Rubber-like polymers and copolymers obtained by ring openingpolymerization of cycloolefines, especially of cyclopentene, are alsosuitable, especially transpolypentenamer.

When using the dispersing agents according to the invention, theproducts obtained are, surprisingly, polycondensation products in theform of beads with a very narrow range of particle sizes. The proportionof beads having a diameter of 0.4 to 0.8 mm can easily be increased topercent in the polycondensate regardless of the method used for mixingthe starting materials. This excellent result is surprisingly much lessdependent on the conditions under which stirring is carried out whenpreparing the suspension in the course of the reaction, for example thespeed of rotation of the stirrer, than when using the low dispersingagents such as polyacrylic esters, halogenated polyolefines orpolystyrene. For a process carried out on a technical scale, this hasthe advantage of providing the required reproducibility and reliabilityof the process.

Moreover, when using the dispersing agents according to the inventionthe process may be carried out with a much more advantageous ratio ofnon-aqueous phase to quantity of suspended condensation product becausemuch more highly concentrated suspensions can be produced without anyloss in quality of the beads of condensate obtained.

EXAMPLE 1 A mixture of 910 parts by weight of chlorobenzene and 1,080parts by weight of o-dichlorobenzene is introduced into a reactionvessel equipped with stirrer, thermometer and dropping funnel. 20 Partsby weight of a cis-l,4-polybutadiene which was prepared by means of atitanium iodide catalyst and according to the IR spectrum contains 94percent of cisl ,4-linkages and has an intrinsic viscosity [1 of 3.6 aredissolved in the aforesaid mixture. 264 Parts by weight of waterfollowed by 205 parts by weight of triethylene tetramine are then slowlyrun into this solution. The suspension is maintained at to C. by coolingwith ice. 313 Parts by weight of epichlorohydrin are added dropwise tothe suspension; the temperature during this time should be kept below 30C. The mixture is then heated on an oil bath for several hours whilebeing constantly stirred at the rate of 220 revs/min. When a temperatureof about 100 C. is reached, an azeotropic mixture of water andchlorobenzene begins to distil. After removal of most of the water, thetemperature is raised to 140 C. and maintained at this level for 2hours. After cooling of the mixture, the beads of resin formed arefiltered from the liquid and then freed by steam distillation fromresidues of solvent adhering thereto. After treatment of the resin withsodium hydroxide solution and washing with water, an anion exchangerhaving a total volumetric capacity of 2.4 Val/l and consisting of morethan 80 percent of particles having a diameter of between 0.4 and 0.8 mmand to an extent of more than 90 percent of particles having a diameterof between 0.3 and 0.8 mm was obtained.

EXAMPLE 2 450 Parts by weight of water and 200 parts by weight ofdiethylene triamine are introduced into a reaction vessel equipped withstirrer, thermometer and dropping funnel. The mixture is stirred andcooled to 30 C. 400 Parts by weight of epichlorohydrin are then addeddropwise, the temperature being kept below 30 C. during this addition.The precondensate is introduced into another reaction vessel containinga solu' tion of 20 parts by weight of cis-1,4-polybutadiene of the typedefined in Example 1 in 1,800 parts by weight of chlorobenzene. Thereaction mixture is stirred at a constant rate of 200 revs/min and theprocedure continues as described in Example 1. An anion exchanger havinga total volumetric capacity of 2.5 Val/l and consisting of more than 80percent of particles having a diameter of between 0.4 and 0.8 mm and toan extent of more than 90 percent of particles having a diameter ofbetween 0.3 and 0.8 mm is obtained.

EXAMPLE 3 1,800 Parts by weight of chlorobenzene are introduced into areaction vessel equipped with stirrer, thermometer and dropping funnel.264 Parts by weight of water followed by 207 parts by weight oftetraethylene pentamine are added with stirring. The mixture ismaintained at a temperature of between 20 and 30 C. by cooling with ice,and 313 parts by weight of epichlorohydrin are added dropwise while thetemperature is maintained below 30 C. 20 Parts by weight of cisl,4-polybutadiene of the type defined in Example 1 are then added anddissolved with stirring at a constant rate adjusted to 220 revs/min. Asuspension of droplets of the condensation mixture in the chlorobenzenephase is formed. The procedure is otherwise as described in Example 1.An anion exchanger having a total volumetric capacity of 2.5 Val/l andcontaining more than 80 percent of particles having a diameter ofbetween 0.4 and 0.8 mm and to an extent of more than percent ofparticles having a diameter of between 0.3 and 0.8 mm is obtained.

EXAMPLE 4 EXAMPLE 5 The method of preparation is the same as in Example1 and the same quantities of starting materials are used except that thecis-l ,4-p0lybutadiene used has been prepared with a cobalt catalyst andcontains 97 percent of cis-l,4-linkages according to the IR spectrum andhas an intrinsic viscosity [1;] of 2.7.

EXAMPLE 6 The method of preparation is the same as in Example 1 and thesame quantities of starting materials are used except that thepolybutadiene used has been prepared with lithium butyl and that itsdouble bonds according to the IR spectrum are 50 percenttrans-1,4-bonds, 43

percent cis-l,4-bonds and 7 percent 1,2-bonds and its intrinsicviscosity [1 is 1.85.

EXAMPLE 7 The method of preparation is the same as described in Example1 and the same quantities of starting materials are used except thatinstead of polybutadiene, an equal quantity of a trans-polypentenamerwhich according to the IR spectrum has 9 1.5 percent of trans doublebonds and which has an intrinsic viscosity [1;] of 2.67 is used.

EXAMPLE 8 The method of preparation and the quantities ofstarting-materials are the same as in Example 1 except that instead ofpolybutadiene an equal quantity of a cisl,4-polyisoprene whichaccording'to the IR spectrum has 94 percent of cis-l,4-bonds and whichhas an intrinsic viscosity [1;] of 1.95 is used.

EXAMPLE 9 The method of preparation and quantities of starting materialsused are the same as in Example 1 except that instead of polybutadienean equal quantity of a statistical butadiene-styrene copolymercontaining 25 percent of styrene and having a Mooney viscosity of ML 4'100 C. 56 is used.

EXAMPLE 10 The method of preparation and quantities of startingmaterials are the same as in Example 1 except that instead ofpolybutadiene, a butadiene-styrene block copolymer containing 25 percentof styrene and having a Mooney viscosity ofML 4'100 C. =50 is used.

EXAMPLE 11 The method of preparation and quantities of startingmaterials used are the same as in Example 1 except that, instead ofpolybutadiene, a statistical butadienestyrene copolymer produced byradical polymerization and containing 23.5 percent of styrene and havinga Mooney viscosity of ML 4' 100C. l 15 is used.

We claim:

1. In the process of suspension condensing epihalohydrin and apolyalkylene polyamine having 1 to NH moities attached to alkylenemoieties having two to four carbon atoms or a precondensate thereof in ahydrocarbon or halogenated hydrocarbon non-solvent in the presence of adispersing agent, the improvement comprising employing as dispersingagent, 0.01 to 5 percent by weight, based on the weight of thenon-solvent, of a member selected from the 4. The polycondensationproduct produced by the process of claim 1.

2. The process of claim 1 wherein said polyalkylene polyamine isselected from the group consisting of diethylene triamine, triethylenetetramine, tetraethylene pentamine and pentaethylene hexamine.
 3. Theprocess of claim 1 wherein said non-solvent is orthodichlorobenzene, amixture of orthodichlorobenzene and chlorobenzene, a mixture oforthodichlorobenzene and isododecane or a mixture oforthodichlorobenzene, chlorobenzene and isododecane.
 4. Thepolycondensation product produced by the process of claim